The present invention relates to improvements in the shelf bracket disclosed in my prior U.S. Pat. No. 4,121,801, issued Oct. 24, 1978. In my prior patent, the shelf bracket included a shelf bracket member of non-metallic material such as particle board having a top shelf supporting surface and a rear abutment surface extending perpendicular to the shelf supporting surface adjacent the lower rear portion of the shelf bracket member, and a rear recessed surface above and offset forwardly from the rear abutment surface. In one embodiment disclosed in my prior patent, the shelf bracket had a first notch extending downwardly from the top shelf supporting surface and spaced forwardly from the rear recessed surface, and a second notch extending forwardly from the rear abutment surface. The shelf bracket member was attached to a supporting surface by a metal shelf attaching bracket having a generally L-shaped configuration and which included a rear leg having an upper mounting plate portion spaced rearwardly from the rear recessed surface with a keyhole shaped opening therein for receiving a headed mounting fastener, and an upper leg extending forwardly from the upper end of the rear leg and having a depending tongue at its forward end extending downwardly into a first notch and the top of the shelf bracket member to take up the horizontal forces, and a second tongue extending forwardly from the lower end of the rear leg into the second notch of the shelf bracket member to take up the vertical loading on the shelf bracket member.
While my prior shelf bracket worked satisfactorily, it was found that, under very heavy loading on the shelf bracket member, the tongues on the shelf attaching bracket tended to flex or bend relative to the respective leg such that they did not uniformly contact the load bearing wall of the respective notch in the bracket member. This caused a stress concentration adjacent the outer portions of the load bearing wall of the notches, which stress concentration was particularly undesirable when the shelf bracket member is formed of a relatively soft material such as particle board or even wood.